In general, a variety of types of shoes, such as hiking boots and golf shoes, in addition to common walking boots frequently worn in daily life are produced and come into the market. In such shoes, one of the most important functions may be said to be comfortable feeling in the feet when walking. Such comfortable feeling of the feet may be said to be based on cushioning.
In order to provide comfortable feeling when a person wears shoes as described above, a cushion function is recognized as being one of the most important functions in the manufacture of shoes, and various proposals for the cushion function are being made. For example, shoes disclosed in U.S. Pat. No. 8,707,583 B2 provide comfortable feeling (cosiness) when a person wears the shoes and provide a less sense of fatigue while walking for a long time by providing an air cushion function through the entry and exit of air.